Hose and hose coupling assembly



United States Patent Wallace MacWilliam Ridgewood, NJ.

May 16, 1968 Dec. 22, 1970 Scovill Manufacturing Company Waterbury,Conn.

a corporation of Connecticut inventor Appl. No. Filed Patented AssigneeHOSE AND HOSE COUPLING ASSEMBLY 3 Claims, 3 Drawing Figs.

0.8. 285/256 Int. Cl. F16! 33/20 Field of Search 285/256, 259, 95,239-255, 257, 258, 174, Mastic; 138/109 References Cited UNITED STATESPATENTS 1/1934 Pentz 285/251 2,453,997 11/1948 Macwilliam 285/2562,485,976 1 H1949 Main 285/256X 2,920,910 H1960 Schnabel 285/256XFOREIGN PATENTS 1,021,245 3/1966 Great Britain 285/242 PrimaryExaminer-Dave W. Arola Attorney-Dallett l-loopes ABSTRACT: The hoseincludes an internal rubber tube, an outer neoprene layer, and anintermediate braided textile layer. The end is disposed in thehose-receiving annulus between the tubular portion and the ferrule ofthe metal coupling. The ferrule is connected to the tubular portion by aconnecting wall. A thermosetting sealing compound covers the end of thehose and is not bonded to at least a portion of the connecting wall. Theferrule is indented in a peripheral zone spaced from the hose end,compressing the hose between the ferrule and the tubular portion of thecoupling.

PATENIED 050221970 I II I III INVENTOR Wahace MacWiHiam ATTORNEY HOSEAND HOSE COUPLING ASSEMBLY This invention relates to a hose and hosecoupling assembly and the method of making it. More specifically, thisinvention relates to a substantially leakproof hose and hose coupling assembly useful in conducting fluorocarbons under conditions of highvtemperature and pressure.

In the past, it has been conventional to employ flexible hoses inautomobile air-conditioning systems, between the refrigerationcomponents. Usually, these hoses have comprised hose and hose couplingassemblies wherein the hose has included an internal tube of syntheticrubber, for instance, an external layer of neoprene or the like and anintermediate layer of textile or wire braiding.

The end of such a hose has been fitted over the tubular portion of ametal coupling and inserted into the coupling ferrule. Thereafter, theferrule has been indented, peripherally compressing the hose in an areaspaced from the hose end. Such an assembly has then been installed inthe system, for instance, between the compressor and condenser. In suchusage, the hose is subjected to pressures up to 300 pounds per squareinch of a fluorocarbon refrigerant and temperatures up to 300. In suchusage, considerable leakage of fluorocarbon has been believed almostinevitable.

In tests required by American automobile manufacturers for hoses to beused in automobile air-conditioning systems, the hose has been partlyfilled with fluorocarbon refrigerant partly in liquid state subjected toa temperature of 250 and has been required to withstand these conditionsfor a period of 3 days. Almost invariably leakage has shown adjacent tothe hose coupling, and it has been found that the leaking gas has passedbetween the internal tube of the hose and the tubular portion of themetal coupling to the end of the hose and has then passed between thecover and the ferrule and also along the braiding and out through theneoprene cover which has been perforated to avoid blistering orseparating away from the braid.

From the examination of samples which underwent tests at temperatures inexcess of 200 F., the compression set of both the tube and the coverapparent. In other words, when the hose is removed from the coupling, itretains the shape of the recess between the ferrule and the tubularportion. A cor relation between this phenomenon and the leakage atpressures considerably lower than those which would have caused leakageprior to set is explainable: the set itself reduces the compression ofthe hose material between the tubular portion and the ferrule.

l have discovered, contrary to what might be expected under thecircumstances, that substantially all leakage may be eliminated by asimple and inexpensive treatment of the hose during assembly.

The present invention provides means for automatically compensating forthe compression set phenomenon to preclude coupling leakage and acts toan extent proportionate to the pressure imposed on the hose line.

Other objects of the invention will be understood from reading thefollowing specification with reference to the drawing wherein:

FIG. 1 is a side elevation, partly in section, of an assembly undergoinga method of manufacture embodying my invention;

FIG. la is a side elevation, partly in section, of the completedassembly embodying my invention;

FIG. 2 is a partial side elevation, partly in section, of a modifiedform of product having been made in accordance with my invention.

Referring more specifically to the-drawings, FIG. 1 shows elements inpartial assembly inaccordance with the invention. The coupling isgenerally designated and comprises a body 12 having tubular portion 14and a ferrule 16 concentric to the tubular portion so as to define atube-receiving annulus 18. The tubular portion may be annularly indentedas shown. The ferrule 16 is connected to the tubular portion by aconnecting wall 20 which may be-stepped as shown to end in an intumedflange 22 which is mechanically secured to the tube portion 14 as byswaging or crimping of the tube portion about the opposite sides of theintumed flange to seal off the annulus 18. A gasket 24 or other sealingmeans is sealingly confined between a deformed portion 26 of the tubeportion 14 and the ferrule 16 so as to enhance the seal.

The rigid coupling 10 has a stop bead 28 and an internally threaded nut30 as is well known in the art.

The hose s generally designated 36 and is formed in a conventionalmanner. It comprises an internal tube 38 which may be a buna-type rubberand a cover 40 which may be of neoprene disposed about tube 38. A layerof braid 42 is disposed intermediate the cover and tube, and serves toreinforce the structure and to hold the cover to the tube. The hose 36is shoved into the annulus 18. A layer of a thermoset sealing compound50 covers the end faces of the tube, cover and braid. This compound isallowed to set at room temperature.

Referring to FIG. 1a, after the final placement of the hose in theannulus, the ferrule 16 is indented in peripheral areas spaced from thehose end so as to compress the hose in these zones. The peripheralindentations aredesigrrated by arrows A, B, and C inFIG. 1a.

The composition of the sealing compound has been found to be important.A suitable sealing compound has been found to be neoprene compound01952, manufactured by US. Rubber Company of Passaic, NJ. This compoundis available in two parts, one of which is the polymerizable neoprenecement, and the other is an accelerator. In use, these two parts aremixed and the mixture is inserted in annulus 18 or applied to the hoseend. The assembly is left undisturbed and curing is accomplished inabout 2 hours at room temperature.

Other therrnosetting compounds including various epoxy resins have beenfound suitable.

Assemblies made in accordance with the above-described invention havebeen found to be virtually leakproof under the abovedescribedfluorocarbon test. The effectiveness is explained as follows. Thesealing compound selected, being not bonded to the parts of theconnecting wall, acts as a piston, its leftward face in FIG. 1 servingas a working surface. Thus, the sealing compound and hose material isacted on by the gas leakage which passes between the tubular portion 14and the hose and reaches the vicinity of connecting wall 20. This urgeshose material rightward as shown in FIG. la, further compressing thehose in the restricted portion under the peripheral indentations A, B,and C cramming more hose material in these areas and avoiding leakagealong the braid and between the hose and ferrule.

Lending support to the explanation above are the results of tests onassemblies made in accordance with the invention. Assemblies tested hadbeen subjected to temperatures of over 200 F. causing the compressionset referred to above. In the tests, a pressure guage designated A wasconnected to the space between the hose and the ferrule. A second gaugeB was installed in the Freon line. Readings were as follows:

Gauge Gauge A, p.s.i. B, p.s.i.

The ratio of A/B was approximately .6 for each set of readings. For thesecond assembly, still made in accordance with the invention, readingswere:

Gauge Gauge A, p.s.i B, p.s.i.

The ratio herewas approximately 5, Theassemblies thus give thecharacteristicsofapressure-activated seal whereby for automotivevehicles.

ea'ch incrementin linejpressure'there is a proportionate incre- 1'me'ntineflectivenessofthe'seal.

*ro assure that thesealing-compound does not bond to i connectingwall20, the connectingwall may be coated with y 'oil orany of thewell-known mold 'release agents such as a silicoi e fluid or grease, orone of the fluorocarbon polymers.

j hose assemblies made in accordance withlthe invention havedemonstrated remarkable versatility operating under temperature andpressure conditions both aboveand below 1 those demanded undei'ithenormal operating conditions of an automobile air-conditioning system.While the assembly under limited number of forms,lit is obvious thatitis not solimiting but us susceptible of a large 'numb'erof modificationsand 'variations, and it'is'intended; that the patent reflected in theappended claim language. a v Iclaim: j l" V 1. A and hose couplingassembly especially adaptedfijruse in conducting fluorocarbons' under 1conditions of high pressure and temperature comprisingza metalcouplingineluding a tubular portion surroundedby a ferrule connected tothe tubular portion by a cdnne'ctingw all to definea hosereceivingannulus; a hose including an internal tube of a bu-na the" invention maybe'found highly satisfactory in conducting ma'ny fluorocarbons Freon 12,a brand of dichlorodifluourmethane, has been; therefrigerant used inmanyof the actual I,

installations.

, A variation of ti reinvention of an 'a ssembly'made in acl cordancewith'the invention is shown in FIG. 2. in the FIG. 2 7 version, thetubular portion 14 is integrally, formed with the ferrule 16? and the"connecting wall 20', The end of the hose 36? is covered withthe'sea'ling compound 50' and an addisealing gasket,52 of rubber orelastometer is engaged by sealing compound. The gasket obviously keepsthe seal irig compound't'ro m beingbonded' to the connectingwvall. As

shown, the ferrule is indented in the peripheral zones indicated by thearrows.

The development of hose coupling assemblies bythe simple expedientsdescribed herein is totally new and wholly unexpected. it will beapparent that this simple inexpensive'imf provement and unconventionalassembly processfills a longfelt need, especially in the field of therefrigeration systems in type rubber; an external cover of neoprene, andan intermediate reinforcing layer of braid, the hose having its'enddisposed inthe annulus, and acured thermosetting sealingcompoundmeanseirtendin'f g from said tubular portion to said ,zonespaced from the hose end.

2. A device as described in claim 1' wherein the thermosettingsealing'compound is a polymerizable neoprene compound. I, V

3. Adevice as described in claim 1 wherein the thermosetting sealingcompound means includes an annular layer of gasket material adjacent theconnecting wall assuring that the means is not bonded totheconnectingwall.

While the inventiori hasbeen shown and described in a i coverage

